Method for hafnium nitride deposition

ABSTRACT

The present invention generally is a method for forming a high-k dielectric layer, comprising depositing a hafnium compound by atomic layer deposition to a substrate, comprising, delivering a hafnium precursor to a surface of the substrate, reacting the hafnium precursor and forming a hafnium containing layer to the surface, delivering a nitrogen precursor to the hafnium containing layer, forming at least one hafnium nitrogen bond and depositing the hafnium compound to the surface.

BACKGROUND OF THE INVENTION

[0001] Field of the Invention

[0002] Embodiments of the present invention generally relate to methodsto deposit materials on substrates, and more specifically, to methodsfor depositing metal oxides, metal nitrides, metal oxynitrides, metalsilicates and metal silicon oxynitrides using atomic layer depositionprocesses.

[0003] In the field of semiconductor processing, flat-panel displayprocessing or other electronic device processing, chemical vapordeposition has played an important role in forming films on substrates.As the geometries of electronic devices continue to shrink and thedensity of devices continues to increase, the size and aspect ratio ofthe features are becoming more aggressive, e.g., feature sizes of 0.07microns and aspect ratios of 10 or greater are being considered.Accordingly, conformal deposition of materials to form these devices isbecoming increasingly important.

[0004] While conventional chemical vapor deposition has provedsuccessful for device geometries and aspect ratios down to 0.15 microns,the more aggressive device geometries require new, innovative depositiontechniques. One technique that is receiving considerable attention isatomic layer deposition (ALD). In the scheme, reactants are sequentiallyintroduced into a processing chamber where each reactant chemisorbs ontothe surface of the substrate and a surface reaction occurs. A purge stepis typically carried out between the delivery of each reactant gas. Thepurge step may be a continuous purge with the carrier gas or a pulsepurge between the delivery of the reactant gases.

[0005] U.S. Pat. No. 6,287,965 describes a method of ALD to form a metalnitride layer having the structure of A-B-N, where A is a metal, B is anelement to prevent crystallization and N is nitrogen. The preferredembodiment teaches a method to make TiAlN. No incorporation of oxygeninto these films is disclosed; in fact, the invention teaches away fromoxygen incorporation by sequentially stacking oxygen diffusion barrierlayers between the metal nitride layers for oxygen protection.

[0006] U.S. Pat. No. 6,200,893, entitled “Radical-assisted SequentialCVD”, describes a method for CVD deposition on a substrate whereinradical species such as hydrogen and oxygen or hydrogen and nitrogen areused in an alternative step with a molecular precursor to form onecycle. A composite integrated film is produced by repetitive cycles ofthe method. In a preferred embodiment, the deposited material from themolecular precursor are metals and the radicals, in the alternate steps,are used to remove ligands left from the metal precursor reactions. Theradicals oxidize or nitridize the metal surface in subsequent layers inorder to respectively yield metal oxide or nitride. In variousembodiments of the reference, metallic hafnium and hafnium oxide aremade from a halogen-containing precursor. However, the reference doesnot address complex hafnium compounds (tertiary, quaternary orpentanary) produced from metal organic compounds. Furthermore, thereference requires the use of radicals to incorporate oxygen and/ornitrogen into the film.

[0007] Therefore, there is a need for a process for depositing hafniumcompounds such as nitrides, silicates, oxynitrides, silicon nitrides,silicon oxynitrides, aluminum oxynitrides and aluminum siliconoxynitrides from organometallic compounds.

SUMMARY OF THE INVENTION

[0008] In one embodiment, the present invention is a method for forminga layer comprising hafnium on a substrate surface, sequentiallycomprising: a) exposing the substrate surface to a hafnium precursor toform a hafnium containing layer on the substrate surface; b) purging thechamber with a purge gas; c) reacting a second precursor with thehafnium containing layer; d) purging the chamber with the purge gas; e)reacting a third precursor with the hafnium containing layer; f) purgingthe chamber with the purge gas; g) reacting a fourth precursor with thehafnium containing layer; and h) purging the chamber with the purge gas.

[0009] In another embodiment, the present invention is a method forgrowing a layer comprising hafnium, comprising exposing a substratesequentially to at least four precursors during an ALD cycle to deposita compound film comprising hafnium and at least three elements selectedfrom the group consisting of silicon, aluminum, oxygen and nitrogen.

[0010] In another embodiment, the present invention is a method fordepositing a hafnium compound on a substrate in a chamber during anatomic layer deposition process, comprising conducting a first halfreaction comprising a hafnium precursor, conducting a second halfreaction comprising an oxygen precursor, conducting a third halfreaction comprising a nitrogen precursor and conducting a fourth halfreaction comprising a silicon precursor.

[0011] In another embodiment, the present invention is a composition ofa semiconductor material, comprising HfSi_(x)O_(y)N_(z), wherein x is atleast about 0.2 and less than about 4, y is at least about 0.5 and lessthan about 4 and z is at least about 0.05 and less than about 2.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] So that the manner in which the above recited features of thepresent invention can be understood in detail, a more particulardescription of the invention, briefly summarized above, may be had byreference to embodiments, some of which are illustrated in the appendeddrawings. It is to be noted, however, that the appended drawingsillustrate only typical embodiments of the invention and are thereforenot to be considered limiting of its scope, for the invention may admitto other equally effective embodiments.

[0013]FIG. 1 is a scheme to show an example of half reactions that areused to grow a hafnium nitride film.

[0014]FIG. 2 is a scheme to show an example of half reactions that areused to grow a hafnium oxide film.

[0015]FIGS. 3A-3D are schemes to show an example of half reactions thatare used to grow a hafnium silicate film.

[0016]FIGS. 4A-4D are schemes to show an example of half reactions thatare used to grow a hafnium silicon oxynitride film.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0017] The present invention provides methods for preparing hafniumcompounds used in a variety applications including high k dielectricmaterials. The methods use atomic layer deposition (ALD) to haveelemental control of the composition of hafnium compounds. The elementalcontrol is generally separated by half reactions.

[0018] Half reactions are abstractly demonstrated via the reaction:

AC+BD→AB+CD,

[0019] wherein AB is the product compound and CD is the secondarycompound or secondary product.

[0020] For example, a half reaction is demonstrated by each of thefollowing steps:

[0021] (1) *NH₂+(Et₂N)₄Hf→*N═Hf(NEt₂)₂+2HNEt₂

[0022] (2) *N═Hf(NEt₂)₂+NH₃→*N═Hf═NH+2HNEt₂,

[0023] wherein the half reaction of step 1 is initiated by thefunctional group NH₂ and * is an atom or molecule that is part of thesubstrate, film or surface group. The hafnium precursor reacts with theNH₂ group and forms a Hf—N bond. Ligands are protonated from the hafniumprecursor to form a secondary product. During the half reaction in step2, ammonia reacts with the hafnium complex bound to the surface. Theremaining ligands are protonated and removed while another Hf—N bond andanother functional group (NH) are formed as the product compound. Ineach half reaction of steps 1 and 2, diethyl amine (HNEt₂) can be madeas a secondary compound. Other secondary compounds are amines andhydrazines and include radicals, ions and variations to ligands, such asEt₂N, (Et₂N)₂, EtNH and (EtNH)₂. Generally, these secondary compoundsare readily removable, such as by vacuum and/or purge. The reactionschemes are not necessarily stoichiometric, but have a wide range ofatomic ratios. Throughout the disclosure, reaction examples lackspecific stoichiometry, bonding order and bonding connectivity of theproduct compounds and secondary compounds.

[0024] Another example of a half reaction is demonstrated by each of thefollowing steps:

[0025] (3) *OH+(Et₂N)₄Hf→*O—Hf(NEt₂)_(x)+HNEt₂

[0026] (4) *O—Hf(NEt₂)_(x)+H₂O→*O—Hf—(OH)+HNEt₂,

[0027] wherein the half reaction of step 3 is initiated by thefunctional OH group and forms a Hf—O bond. Step 4 proceeds to formanother Hf—O bond as well as the terminus and functional OH group.

[0028] Therefore, in general, a first half reaction initiates with thereaction of a first functional group, establishes at least one productcompound bond and establishes a second functional group. The second halfreaction initiates with a reaction of the second functional group,establishes at least one product compound bond and establishes a thirdfunctional group. The third functional group, in many examples, is thesame or similar to the first functional group. However, the second halfreaction is still complete even when the third functional group isdifferent. Examples with tertiary, quaternary and higher productcompounds require half reactions with more than two precursors.Therefore, half reactions are not limited to only binary productcompounds and may contain any number of half reactions. Most halfreactions are sequentially separated by gas and/or vacuum purges.

[0029] Embodiments of the processes described herein deposithafnium-containing materials on many substrates and surfaces. Substrateson which embodiments of the invention may be useful include, but are notlimited to semiconductor wafers, such as crystalline silicon (e.g.,Si<100> or Si<111>), silicon oxide, silicon germanium, doped or undopedpolysilicon, doped or undoped silicon wafers silicon nitride andpatterned or non-patterned wafers. Surfaces include bare silicon wafers,films, layers and materials with dielectric, conductive and barrierproperties and include aluminum oxide and polysilicon. Pretreatment ofsurfaces includes polishing, etching, reduction, oxidation,hydroxylation, annealing and baking.

[0030] A substrate can be pretreated to be terminated with a variety offunctional groups such as hydroxyls (OH), alkoxy (OR, where R=Me, Et, Pror Bu), haloxyls (OX, where X=F, Cl, Br or 1), halides (F, Cl, Br or 1),oxygen radicals, aminos (NH or NH₂) and amidos (NR or NR₂, where R=Me,Et, Pr or Bu). A pretreatment can be accomplished by administering areagent, such as NH₃, B₂H₆, SiH₄, SiH₆, H₂O, HF, HCl, O₂, O₃, H₂O₂, H₂,atomic-H, atomic-N, atomic-O, alcohols or amines.

[0031] Once the surface of the substrate is pretreated, an ALD cycle isstarted. For many of the hafnium compounds, the hafnium precursoradsorption is self-limiting under certain process conditions, andgenerally must be at low temperatures (<500° C.) to exhibit thisbehavior. Some examples of half reactions that are self-limiting for thehafnium precursor include:

*NH₂+(Et₂N)₄Hf→*N═Hf(NEt₂)₂+2HNEt₂

*NH+(Et₂N)₄Hf→*N—Hf(NEt₂)₃+HNEt₂

*OH+(Et₂N)₄Hf→*O—Hf(NEt₂)₃+HNEt₂

[0032] wherein, hafnium is added to produce either *O—Hf(NEt₂)_(x) or*N—Hf(NEt₂)_(x). An atom, such as a nitrogen or oxygen, can anchor thehafnium atom to the substrate or surface. *Hf(NEt₂)_(x) is self-limitingbecause the hafnium precursor will not react further; therefore, this isthe first half reaction. To proceed with other half reactions, either anoxygen source (e.g., water) or a nitrogen source (e.g., ammonia) isadded.

[0033] The first half reaction with a hafnium precursor initiates aseries of many half reactions to make binary, tertiary, quaternary andmore complex compounds. The first half reaction does not have to includea hafnium precursor, but can include any precursor to which a particularelement is incorporated into the film. The following examples willportray hafnium precursors as the first half reaction in order to moreclearly explain aspects of the invention.

[0034] One embodiment of the invention is directed to a process whichproceeds with the half reaction of NH₃ to *Hf(NEt₂)_(x) to produce*Hf—NH. Hafnium nitride is synthesized by sequentially proceeding with ahalf reaction of the hafnium precursor and a half reaction of a nitrogensource. FIG. 1 depicts a half reaction which is initiated by dosing(Et₂N)₄Hf from about 0.01 second to about 10 seconds, preferably about0.25 second and dosing an inert gas purge from about 0.01 second toabout 20 seconds, preferably about 0.25 second. A second half reactionis then initiated by dosing NH₃ from about 0.01 second to about 10seconds, preferably about 0.25 second and dosing an inert gas purge fromabout 0.01 second to about 20 seconds, preferably about 0.25 second. Thetwo half reactions are cycled several times to grow a hafnium nitridefilm at the rate of about 50 ng/cm² per cycle. By varying the cycletime, temperature, pressure and/or concentration, stoichiometry of theproduct compound is controlled. Slight variations of the stoichiometrycan have an impact on the electrical properties, e.g., Hf₃N₄ is aninsulating material while HfN is a conducting material. In oneembodiment, HfN is made from a nitrate-free hafnium precursor. Hafniumnitride films can have oxygen contamination, since nitrates contain anoxygen/nitrogen ratio of three.

[0035] In one embodiment, a method for forming a semiconductor materialby atomic layer deposition includes pulsing a hafnium precursor and anitrogen precursor sequentially and cyclically. The hafnium nitride isdeposited to the substrate surface wherein the hafnium nitride has aformula HfN_(x) and x is at least about 1.1 and less than about 1.3. Inone aspect, the hafnium precursor is TDEAH and the nitrogen precursor isNH₃. In another aspect, the hafnium precursor is HfCl4 and the nitrogenprecursor is a radical nitrogen, such as atomic nitrogen.

[0036] Another embodiment of the invention is directed to a processwhich proceeds with the half reaction of H₂O to *Hf(NEt₂)_(x) andproduce *Hf—OH. Hafnium oxide is synthesized by sequentially proceedingwith a half reaction of the hafnium precursor and a half reaction of anoxygen source. FIG. 2 depicts a half reaction which is initiated bydosing (Et₂N)₄Hf from about 0.01 second to about 10 seconds and an inertgas purge dosed for about 0.01 second to about 20 seconds. A second halfreaction is then initiated by dosing H₂O from about 0.01 second to about10 seconds and an inert gas purge from about 0.01 second to about 20seconds. The two half reaction are cycled several times to grow ahafnium oxide film at the rate of about 1.2 Å per cycle.

[0037] The processes to grow the hafnium nitride or hafnium oxide films,as described above, can be modified to achieve other materials, namelytertiary compounds. Hafnium nitride is porous and reacts with water toform hafnium oxynitride, Hf—O—N. Therefore, to the hafnium nitridecycle, a half reaction of an oxygen source (e.g., water) is added tosynthesize hafnium oxynitride. The ratio of Hf:O:N is controlled andvaried to the desired characteristics of the product compound. In oneembodiment, an oxygen precursor half reaction is included into the halfreaction cycle. Such a cycle comprises a hafnium precursor halfreaction, a nitrogen precursor half reaction, another hafnium precursorhalf reaction and an oxygen precursor half reaction. The oxygenprecursor half reaction can be added into the cycle at any ratiorelative to the hafnium and nitrogen precursor half reactions. As anexample, an oxygen precursor half reaction is added at every tencomplete cycles of hafnium and nitrogen precursor half reactions.Furthermore, the ratio can be varied in order to control the oxygenstoichiometry by film depth. Hence, a graded film is formed. In oneembodiment, the process conditions are as follows, pressure is about 1Torr, temperature is about 225° C., argon carrier flow is about 200sccm, H₂O and NH₃ are dosed into the argon carrier flow in the rangefrom about 1 second to about 4 seconds and TDEAH is dosed at about 20seconds.

[0038] Graded films can be used to transition between various materials.One embodiment uses the method to transition between hafnium nitride andhafnium oxide. Within the hafnium nitride film, the elemental ratiosN:Hf:O start out at 10:10:0, progress to 10:10:1, progress to 5:10:5,progress to 1:10:10 and finally 0:10:10, such that the film at theexposed surface following deposition is hafnium oxide. Graded films haveadvantageous characteristics, such as allowing control of electricalproperties throughout the depth of the film, as well as higher levels offilm adhesion.

[0039] Additional embodiments include methods to synthesize hafniumoxynitride. Due to the porosity of hafnium nitride, multiple layers aresusceptible to oxygen enrichment. Instead of incorporating oxygen intoeach surface layer via half reactions, an excess oxygen precursor (e.g.,water) is used to penetrate multiple layers of hafnium nitride and forma hafnium oxynitride graded film such as:

HfN—HfN—HfN—HfN—HfN+xsH₂O→HfN—HfN—HfON—HfON—HfON.

[0040] Therefore, hafnium nitride can be formed by ALD, CVD, PVD orother techniques and thereafter oxygenated with an oxygen precursor.

[0041] Other embodiments of the invention include methods to synthesizetertiary hafnium nitride compounds incorporating silicon. Preferredsilicon precursor compounds include (Me₂N)₄Si and (Me₂N)₃SiH. In oneembodiment, a silicon precursor half reaction is included into the halfreaction cycle for hafnium nitride formation. The cycle includes ahafnium precursor half reaction, a nitrogen precursor half reaction, asilicon precursor half reaction and another nitrogen precursor halfreaction. The silicon precursor half reaction is added into the cycle atany ratio relative to the hafnium and nitrogen precursor half reactions.As an example, a silicon precursor half reaction is added about at everytwo complete cycles of hafnium and nitrogen precursor half reactions.Furthermore, the ratio can be varied in order to control the ratio ofthe silicon incorporated by depth of the film. Similarly to hafniumoxynitride, the method enables control of the Hf:Si:N stoichiometry.

[0042] Other embodiments of the invention are methods to synthesizetertiary hafnium oxide compounds incorporating nitrogen. Similarly asdiscussed above, the method reverses to use of oxygen and nitrogen tosynthesize hafnium oxynitride. In one embodiment, a nitrogen precursorhalf reaction is included into the half reaction cycle of hafnium oxide.The cycle comprises a hafnium precursor half reaction, an oxygenprecursor half reaction, another hafnium precursor half reaction and anitrogen precursor half reaction. The nitrogen precursor half reactionis added into the cycle at any ratio relative to the hafnium and oxygenprecursor half reactions. As an example, a nitrogen precursor halfreaction is added at every two complete cycles of hafnium and oxygenprecursor half reactions. Furthermore, the ratio can be varied in orderto control the ratio of the nitrogen incorporated by depth of thegrowing film.

[0043] Other embodiments of the invention include methods to synthesizetertiary hafnium oxide compounds incorporating silicon, namely hafniumsilicate (Hf—Si—O), as depicted in FIGS. 3A-3D. In one embodiment, asilicon source half reaction is included into the half reaction cycle ofhafnium oxide. The cycle comprises a silicon precursor half reaction, anoxygen precursor half reaction, a hafnium precursor half reaction andanother oxygen precursor half reaction. Purges occur between each halfreaction. The silicon precursor half reaction can be added into thecycle at any ratio relative to the hafnium and oxygen precursor halfreactions. As an example, a silicon precursor half reaction is added atevery two complete cycles of hafnium and oxygen precursor halfreactions. Furthermore, the ratio can be varied in order to control theratio of the silicon incorporated by depth of the film.

[0044] Embodiments of the invention include multiple methods tosynthesize quaternary compounds, especially hafnium silicon oxynitride(HfSiON), as depicted in FIGS. 4A-4D. Methods to synthesize two tertiarycompounds (HfSiO and HfSiN) are modified to respectively nitridized oroxidized within the cycles to form the quaternary complex HfSiON. Halfreactions of nitrogen, oxygen or silicon precursors are added atparticular cycles, providing complete control to the N:O:Si ratiosrelative to hafnium.

[0045] In one embodiment, a nitrogen source half reaction is includedinto the half reaction cycle of hafnium silicate. Such a cycle comprisesa silicon precursor half reaction, an oxygen precursor half reaction, ahafnium precursor half reaction and a nitrogen precursor half reaction.The nitrogen precursor half reaction can be added into the cycle at anyratio relative to the hafnium, silicon and oxygen precursor halfreactions. As an example, a nitrogen precursor half reaction can beadded at about every two complete cycles of hafnium, silicon and oxygenprecursor half reactions. Furthermore, the cycle ratio can be varied inorder to control the nitrogen ratio incorporated within film depth. Someembodiments grow hafnium silicon oxynitride graded films with higherconcentrations of nitrogen near the top of the film.

[0046] In one aspect, the surface is terminated with a *SiOH group. Thehalf reaction cycles are conducted with a hafnium precursor, a nitrogenprecursor, a silicon precursor and an oxygen precursor, each separatedwith a purge. The respective precursors can be TDEAH, ammonia, Tris-DMASand water. In another aspect, the respective precursors are HfCl₄,radical nitrogen, Si₂Cl₆ and O₃. The composition is controlled to form asemiconductor material, comprising HfSi_(x)O_(y)N_(z), wherein x is atleast about 0.2 and less than about 4, y is at least about 0.5 and lessthan about 4 and z is at least about 0.05 and less than about 2.

[0047] Embodiments of the invention include multiple methods tosynthesize pentanary compounds, especially hafnium aluminum siliconoxynitride (HfAlSiON). Half reactions of hafnium, aluminum, nitrogen,oxygen and silicon precursors are added at particular cycles, providingcomplete control to the Al:N:O:Si ratios relative to hafnium. In oneaspect of the process, one cycle of half reaction pulses will include,in the respective order, water, TDEAH, ammonia, Tris-DMAS, water andTMA. In another aspect of the process, one cycle of half reaction pulseswill include, in the respective order, water, HfCl₄, ammonia, Tris-DMAS,water and TMA.

[0048] Therefore, any stoichiometry of the following compounds is madeby methods of the process: HfO, HfN, HfON, HfSiO, HfSiN, HfSiON, HfAlO,HfAlN, HfAlON, HfSiAlO, HfSiAlN, HfSiAlON. Therefore, ALD providesstoichiometric control during the deposition of product compounds. Thestoichiometry may be altered by various procedures following thedeposition process, such as when Hf₃N₄ is thermally annealed to formHfN. Stoichiometry is also controlled by altering the precursor ratiosduring deposition.

[0049] Many industrial applications exist for the product compoundssynthesized by the various embodiments of the invention. Within themicroelectronics industry, the product compounds are used as high-ktransistor gate dielectric materials, transistor gate interfaceengineering, high-k capacitor dielectric materials (DRAMs), seed layers,diffusion barrier layers, adhesion layers, insulator layers, conductinglayers and functionalized surface groups for patterned surfaces (e.g.,selective deposition). In the realm of microelectromechanical systems(MEMS), the materials formed by the claimed invention are used asinsulating, conducting or structural films. The materials can also serveas functionalized surface groups to reduce stiction. Additionalfunctionality of surface groups is used in gas or liquid chromatography,chemical sensors and active sites for chemical attachment, patternedsurfaces (e.g., combinatorial chemistry). Silicon nitride is also usedas a hardening coating on tools and within optical devices.

[0050] Many precursors are within the scope of the invention. Oneimportant precursor characteristic is to have a favorable vaporpressure. Precursors may be a plasma, gas, liquid or solid at ambienttemperature and pressure. However, within the ALD chamber, precursorsare volatilized. Organometallic compounds or complexes include anychemical containing a metal and at least one organic group, such asalkyls, alkoxyls, alkylamidos and anilides. Precursors comprise oforganometallic and halide compounds.

[0051] Exemplary hafnium precursors include hafnium compounds containingligands such as alkylamidos, cyclopentadienyls, halides, alkyls,alkoxides and combinations thereof. Alkylamido hafnium compounds used ashafnium precursors include (RR′N)₄Hf, where R or R′ are independentlyhydrogen, methyl, ethyl, propyl or butyl. Specific hafnium precursorsinclude: (Et₂N)₄Hf, (Me₂N)₄Hf, (EtMeN)₄Hf), (^(t)BuC₅H₄)₂HfCl₂,(C₅H₅)₂HfCl₂, (EtC₅H₄)₂HfCl₂, (Me₅C₅)₂HfCl₂, (Me₅C₅)HfCl₃,(^(i)PrC₅H₄)₂HfCl₂, (^(i)PrC₅H₄)HfCl₃, (^(t)BuC₅H₄)₂HfMe₂, (acac)₄Hf,(hfac)₄Hf, (tfac)₄Hf, (thd)₄Hf, Br₄Hf, Cl₄Hf, 1₄Hf, (NO₃)₄Hf,(^(t)BuO)₄Hf, (^(i)PrO)₄Hf, (EtO)₄Hf and (MeO)₄Hf.

[0052] Exemplary silicon precursors include: alkylamidosilanes (e.g,(Me₂N)₄Si, (Me₂N)₃SiH, (Me₂N)₂SiH₂, (Me₂N)SiH₃, (Et₂N)₄Si, (Et₂N)₃SiH),Si(NCO)₄, MeSi(NCO)₃, SiH₄, Si₂H₆, SiCl₄, Si₂Cl₆, MeSiCl₃, HSiCl₃,Me₂SiCl₂, H₂SiCl₂, silanols (e.g., MeSi(OH)₃, Me₂Si(OH)₂), (EtO)₄Si andvarious alkoxy silanes (e.g., (RO)_(4-n)SiL_(n), where R=methyl, ethyl,propyl and butyl and L=H, OH, F, Cl, Br or I and mixtures thereof).Also, higher silanes are used as silicon precursors by processes of theinvention. Higher silanes are disclosed in U.S. provisional patentapplication 60/419,426, 60/419,376 and 60/419,504, each filed on Oct.18, 2002, assigned to Applied Material, Inc., and each entitled, “Lowtemperature deposition with silicon compounds” and are incorporatedherein by reference in entirety for the purpose of describing siliconprecursors.

[0053] Exemplary nitrogen precursors include: NH₃, N₂, hydrazines (e.g.,N₂H₄ or MeN₂H₃), amines (e.g., Me₃N, Me₂NH or MeNH₂), anilines (e.g.,C₆H₅NH₂), organic azides (e.g., MeN₃ or Me₃SiN₃), inorganic azides(e.g., NaN₃ or Cp₂CoN₃) and radical nitrogen compounds (e.g., N₃, N₂, N,NH or NH₂). Radical nitrogen compounds can be produced by heat,hot-wires and/or plasma.

[0054] Exemplary oxygen precursors include: H₂O, H₂O₂, O₃, O₂, NO, N₂O,NO₂, N₂O₅, alcohols (e.g., ROH, where R=Me, Et, Pr and Bu), peroxides(organic and inorganic) carboxylic acids and radical oxygen compounds(e.g., O, O₂, O₃ and OH radicals). Radical oxygen compounds can beproduced by heat, hot-wires and/or plasma.

[0055] Exemplary aluminum precursors include: aluminum alkyls such as:Me₃Al, Et₃Al, Pr₃Al, Bu₃Al, Me₂AlH, Et₂AlH, Me₂AlCl, Et₂AlCl, aluminumalkoxyls such as: (MeO)₃Al, (EtO)₃Al, (PrO)₃Al and (BuO)₃Al, aluminumdimmers, aluminum halides and aluminum hydrides.

[0056] The processes of the invention can be carried out in equipmentknown in the art of ALD. The apparatus brings the sources into contactwith a heated substrate on which the films are grown. Hardware that canbe used to deposit films is an ALD apparatus as disclosed in U.S. patentapplication Ser. No. 10/251,715, filed Sep. 20, 2002, assigned toApplied Material, Inc., Santa Clara, Calif. and entitled “An Apparatusfor the Deposition of High Dielectric Constant Films”, and isincorporated herein by reference in entirety for the purpose ofdescribing the apparatus. Carrier gases or purge gases include N₂, Ar,He, H₂, forming gas and mixtures thereof.

[0057] In one embodiment, hydrogen gas is applied as a carrier gas,purge and/or a reactant gas to reduce halogen contamination from thefilm. Precursors that contain halogen atoms (e.g., HfCl₄, SiCl₄ andSi₂Cl₆) readily contaminate the film. Hydrogen is a reductant and willproduce hydrogen chloride as a volatile and removable by-product.Therefore, hydrogen is used as a carrier gas or reactant gas whencombined with a precursor compound (i.e., hafnium, silicon, aluminum,oxygen or nitrogen precursors) and can include another carrier gas(e.g., Ar or N₂). In one aspect, a water/hydrogen mixture, at atemperature in the range from about 250° C. to about 650° C., is used toreduce the halogen concentration and increase the oxygen concentrationof the film.

[0058] The present invention provides methods for preparing thefollowing compounds. The subscripts (w, x, y, z) imply thatstoichiometry is intentionally varied (i.e., compositionally controlled)via ALD dosing sequences to form the following product compounds:hafnium aluminate: HfAl_(x)O_(y) hafnium oxide: HfO₂ and HfO_(x) hafniumnitride: Hf₃N₄, HfN and HfN_(x) hafnium oxynitride: HfO_(x)N_(y) hafniumaluminum oxynitride: HfAl_(x)O_(y)N_(z) hafnium silicate: HfSiO₄,Hf₄SiO₁₀, Hf₃SiO₈, Hf₂SiO₆, HfSiO₂, Hf_(x)Si_(y)O_(2(x+y)) andHf_(x)Si_(y)O aluminum silicate: Al₆Si₂O₁₃ and Al_(x)Si_(y)O hafniumaluminum silicate: Hf₂Al₆Si₄O₂₁ and Hf_(x)Al_(y)Si_(z)O hafnium siliconnitride: Hf_(x)Si_(y)N hafnium silicon oxynitride: Hf₂Si₂N₂O₅ andHfSi_(x)O_(y)N_(z) aluminum silicon oxynitride: AlSi_(x)O_(y)N_(z)hafnium aluminum silicon HfAl_(w)Si_(x)O_(y)N_(Z) oxynitride:

[0059] The list of product compounds is only partial and other materialsare prepared with the methods of the invention. Other elements, such ascarbon, titanium, tungsten, ruthenium, tantalum, zirconium, molybdenum,iridium, nickel, copper, tin, boron or phosphorus may be incorporatedinto the films as product compounds. Therefore, a product compound maycomprise hafnium silicon oxynitride and carbon. Examples of halfreactions are listed below. Note, that *=surface species.

[0060] Reactivity of Precursors with Surface Hydroxyl Groups (—OH)

Al—OH*+TDMAS_((g))→Al—O—Si(N(CH₃)₂)*+xsHN(CH₃)_(2(g))

Al—OH*+TrisDMAS_((g))→Al—O—SiH(N(CH₃)₂)*+xsHN(CH₃)_(2(g))

Al—OH*+TrisDMAS_((g))→Al—O—Si(N(CH₃)₂)*+xsHN(CH₃)_(2(g))+H_(2(g))

Al—OH*+TDEAH_((g))→Al—O—Hf(N(CH₂CH₃)₂)*+xsHN(CH₂CH₃)_(2(g))

Al—OH*+TMA_((g))→Al—O—AlCH₃ *+xsCH_(4(g))

Hf—OH*+TDMAS_((g))→Hf—O—Si(N(CH₃)₂)*+xsHN(CH₃)_(2(g))

Hf—OH*+TrisDMAS_((g))→Hf—O—SiH(N(CH₃)₂)*+xsHN(CH₃)_(2(g))

Hf—OH*+TrisDMAS_((g))→Hf—O—Si(N(CH₃)₂)*+xsHN(CH₃)_(2(g))+H_(2(g))

Hf—OH*+TDEAH_((g))→Hf—O—Hf(N(CH₂CH₃)₂)*+xsHN(CH₂CH₃)_(2(g))

Hf—OH*+TMA_((g))→Hf—O—AlCH₃ *+xsCH_(4(g))

Si—OH*+TDMAS_((g))→Si—O—Si(N(CH₃)₂)*+xsHN(CH₃)_(2(g))

Si—OH*+TrisDMAS_((g))→Si—O—SiH(N(CH₃)₂)*+xsHN(CH₃)_(2(g))

Si—OH*+TrisDMAS_((g))→Si—O—Si(N(CH₃)₂)*+xsHN(CH₃)_(2(g))+H_(2(g))

Si—OH*+TDEAH_((g))+Si—O—Hf(N(CH₂CH₃)₂)*+xsHN(CH₂CH₃)_(2(g))

Si—OH*+TMA_((g))→Si—O—AlCH₃ *+xsCH_(4(g))

[0061] Reactivity of Surface Products with H₂O_((g)) to RegenerateSurface Hydroxyl (—OH) Groups.

Al—O—Si(N(CH₃)₂)*+H₂O→Al—O—Si(OH)*+xsHN(CH₃)_(2(g))

Al—O—SiH(N(CH₃)₂)*+H₂O→Al—O—SiH(OH)*+xsHN(CH₃)_(2(g))

Al—O—SiH(N(CH₃)₂)*+H₂O→Al—O—Si(OH)*+xsHN(CH₃)_(2(g))+H_(2(g))

Al—O—Si(N(CH₃)₂)*+H₂O→Al—O—Si(OH)*+xsHN(CH₃)_(2(g))

Al—O—Hf(N(CH₂CH₃)₂)*+H₂O→Al—O—Hf(OH)*+xsHN(CH₂CH₃)_(2(g))

Al—O—AlCH₃*+H₂O→Al—O—Al(OH)*+xsCH_(4(g))

Hf—O—Si(N(CH₃)₂)*+H₂O→Hf—O—Si(OH)*+xsHN(CH₃)_(2(g))

Hf—O—SiH(N(CH₃)₂)*+H₂O→Hf—O—SiH(OH)*+xsHN(CH₃)_(2(g))

Hf—O—SiH(N(CH₃)₂)*+H₂O→Hf—O—Si(OH)*+xsHN(CH₃)_(2(g))+H_(2(g))

Hf—O—Si(N(CH₃)₂)*+H₂O→Hf—O—Si(OH)*+xsHN(CH₃)_(2(g))

Hf—O—Hf(N(CH₂CH₃)₂)*+H₂O→Hf—O—Hf(OH)*+xsHN(CH₂CH₃)_(2(g))

Hf—O—AlCH₃*+H₂O∝Hf—O—Al(OH)*+xsCH_(4(g))

Si—O—Si(N(CH₃)₂)*+H₂O∝Si—O—Si(OH)*+xsHN(CH₃)_(2(g))

Si—O—SiH(N(CH₃)₂)*+H₂O→Si—O—SiH(OH)*+xsHN(CH₃)_(2(g))

Si—O—SiH(N(CH₃)₂)*+H₂O→Si—O—Si(OH)*+xsHN(CH₃)_(2(g))+H_(2(g))

Si—O—Si(N(CH₃)₂)*+H₂O∝Si—O—Si(OH)*+xsHN(CH₃)_(2(g))

Si—O—Hf(N(CH₂CH₃)₂)*+H₂O∝Si—O—Hf(OH)*+xsHN(CH₂CH₃)_(2(g))

Si—O—AlCH₃*+H₂O→Si—O—Al(OH)*+xsCH_(4(g))

[0062] Reactivity of Surface Products with NH_(3(g)) to Generate SurfaceAmine (—NH₂, —NH) Groups.

Al—O—Si(N(CH₃)₂)*+NH₃→Al—O—Si(NH₂)*+xsHN(CH₃)_(2(g))

Al—O—SiH(N(CH₃)₂)*+NH₃→Al—O—SiH(NH₂)*+xsHN(CH₃)_(2(g))

Al—O—SiH(N(CH₃)₂)*+NH₃→Al—O—Si(NH)*+xsHN(CH₃)_(2(g))+H_(2(g))

Al—O—Si(N(CH₃)₂)*+NH₃→Al—O—Si(NH₂)*+xsHN(CH₃)_(2(g))

Al—O—Hf(N(CH₂CH₃)₂)*+NH₃→Al—O—Hf(NH₂)*+xsHN(CH₂CH₃)_(2(g))

Al—O—AlCH₃*+NH_(2(p))→Al—O—Al(NH₂)*+xsCH_(4(g))

Hf—O—Si(N(CH₃)₂)*+NH_(3→Hf—O—Si(OH)*+) xsHN(CH₃)_(2(g))

Hf—O—SiH(N(CH₃)₂)*+NH_(3→Hf—O—SiH(NH)*+) xsHN(CH₃)_(2(g))

Hf—O—SiH(N(CH₃)₂)*+NH₃→Hf—O—Si(NH)*+xsHN(CH₃)_(2(g))+H_(2(g))

Hf—O—Si(N(CH₃)₂)*+NH₃→Hf—O—Si(NH)*+xsHN(CH₃)_(2(g))

Hf—O—Hf(N(CH₂CH₃)₂)*+NH₃→Hf—O—Hf(NH)*+xsHN(CH₂CH₃)_(2(g))

Hf—O—AlCH₃*+NH_(2(p))→Hf—O—Al(NH)*+xsCH_(4(g))

Si—O—Si(N(CH₃)₂)*+NH_(3→Si—O—Si(NH)*+) xsHN(CH₃)_(2(g))

Si—O—SiH(N(CH₃)₂)*+NH₃→Si—O—SiH(NH)*+xsHN(CH₃)_(2(g))

Si—O—SiH(N(CH₃)₂)*+NH₃→Si—O—Si(NH)*+xsHN(CH₃)_(2(g))+H_(2(g))

Si—O—Si(N(CH₃)₂)*+NH₃→Si—O—Si(NH)*+xsHN(CH₃)_(2(g))

Si—O—Hf(N(CH₂CH₃)₂)*+NH₃→Si—O—Hf(NH)*+xsHN(CH₂CH₃)_(2(g))

Si—O—AlCH₃*+NH_(2(p))→Si—O—Al(NH)*+xsCH_(4(g))

[0063] Reactivity of Precursors with Surface Amine Groups (—NH or —NH₂)

Hf—NH*+TrisDMAS_((g))→Hf—N—SiH(N(CH₃)₂)*+xsHN(CH₃)_(2(g))

Hf—NH*+TrisDMAS_((g))→Hf—N—Si(N(CH₃)₂)*+xsHN(CH₃)_(2(g))+H_(2(g))

Hf—NH*+TDEAH_((g))→Hf—N—Hf(N(CH₂CH₃)₂)*+xsHN(CH₂CH₃)_(2(g))

Hf—NH*+TMA_((g))→Hf—N—AlCH₃ *+xsCH_(4(g))

Si—NH*+TrisDMAS_((g))→Si—N—SiH(N(CH₃)₂)*+xsHN(CH₃)_(2(g))

Si—NH*+TrisDMAS_((g))→Si—N—Si(N(CH₃)₂)*+xsHN(CH₃)_(2(g))+H_(2(g))

Si—NH*+TDEAH_((g))→Si—N—Hf(N(CH₂CH₃)₂)*+xsHN(CH₂CH₃)_(2(g))

Si—NH*+TMA_((g))→Si—N—Al(CH₃)*+xsHN(CH₂CH₃)_(2(g))

[0064] Reactivity of Surface products with NH₃ to Regenerate SurfaceAmine Groups.

Hf—N—SiH(N(CH₃)₂)*+NH_(3(g))→Hf—N—Si(NH)*+xsHN(CH₃)_(2(g))+H_(2(g))

Hf—N—SiH(N(CH₃)₂)*+NH_(3(g))→Hf—N—SiH(NH₂)*+xsHN(CH₃)_(2(g))

Hf—N—Si(N(CH₃)₂)*+NH_(3(g))→Hf—N—Si(NH₂)*+xsHN(CH₃)_(2(g))

Hf—N—Hf(N(CH₂CH₃)₂)*+NH_(3(g))→Hf—N—Hf(NH₂)*+xsHN(CH₂CH₃)_(2(g))

Hf—N—AlCH₃*+NH_(2(p))→Hf—N—Al(NH₂)*+xsHN(CH₂CH₃)_(2(g))

Hf—N—SiH(N(CH₃)₂)*+NH_(3(g))→Si—N—Si(NH)*+xsHN(CH₃)_(2(g))+H_(2(g))

Hf—N—SiH(N(CH₃)₂)*+NH_(3(g))→Si—N—SiH(NH₂)*+xsHN(CH₃)_(2(g))

Si—N—Si(N(CH₃)₂)*+NH_(3(g))→Si—N—Si(NH₂)*+xsHN(CH₃)_(2(g))

Si—N—Hf(N(CH₂CH₃)₂)*+NH_(3(g))→Si—N—Hf(NH₂)*+xsHN(CH₂CH₃)_(2(g))

Si—N—Al(CH₃)*+NH_(2(p))→Si—N—Al(NH₂)*+xsHN(CH₂CH₃)_(2(g))

[0065] Reactivity of Surface Products With H₂O_((g)) to Generate SurfaceHydroxyl Groups.

Hf—N—SiH(N(CH₃)₂)*+H₂O→Hf—N—Si(OH)*+xsHN(CH₃)_(2(g))+H_(2(g))

Hf—N—SiH(N(CH₃)₂)*+H₂O @ Hf—N—SiH(OH)*+xsHN(CH₃)_(2(g))

Hf—N—Si(N(CH₃)₂)*+H₂O→Hf—N—Si(OH)*+xsHN(CH₃)_(2(g))

Hf—N—Hf(N(CH₂CH₃)₂)*H₂O→ Hf—N—Hf(OH)*+xsHN(CH₂CH₃)_(2(g))

Hf—N—AlCH₃*+H₂O∝Hf—N—Al(OH)*+xsCH_(4(g))

Si—N—SiH(N(CH₃)₂)*+H₂O→Si—N—Si(OH)*+xsHN(CH₃)_(2(g))+H_(2(g))

Si—N—SiH(N(CH₃)₂)*+H₂O→Si—N—SiH(OH)*+xsHN(CH₃)_(2(g))

Si—N—Si(N(CH₃)₂)*+H₂O→Si—N—Si(OH)*+xsHN(CH₃)_(2(g))

Si—N—Hf(N(CH₂CH₃)₂)*+H₂O→Si—N—Hf(OH)*+xsHN(CH₂CH₃)_(2(g))

Si—N—Al(CH₃)*+H₂O→Si—N—Al(OH)*+xsHN(CH₂CH₃)_(2(g))

EXAMPLES

[0066] TDEAH = tetrakisdiethylamidohafnium = (Et₂N)₄Hf TDMAS =tetrakisdimethlaminosilicon = (Me₂N)₄Si TrisDMAS =trisdimethylaminosilicon = (Me₂N)₃SiH TMA = trimethyl aluminum = Me₃Al

[0067] The ALD processes are maintained in a temperature range fromabout 20° C. to about 650° C., preferably from about 150° C. to about300° C., more preferably at about 225° C. Materials grown may be similarthroughout a wider temperature range assuming that saturating ALDbehavior is maintained. The ALD processes are conducted with a pressurein the range from about 0.1 Torr to about 100 Torr, preferably in therange from about 1 Torr to about 10 Torr. Materials grown may be similarfrom high vacuum to high pressures assuming saturating ALD behavior ismaintained. The flow is maintained viscous to encourage reactantseparation. Carrier gas (e.g., N₂) is maintained in the range from about50 sccm to about 1,000 sccm, preferably at about 300 sccm with a speedof about 1 m/s. Higher speeds may create particle transport issues whilelower speeds could allow particle formation due to inefficient purging,affecting electrical behavior of thin films. Films are deposited withthickness in the range from about 2 Å to about 1,000 Å, preferably, fromabout 5 Å to about 100 Å, and more preferably in the range from about 10Å to about 50 Å.

[0068] In one example, a hafnium oxide film is grown by ALD in thepresence of hydrogen gas. Hydrogen is used to reduce levels of halogencontaminates (e.g., F or Cl) within hafnium-containing films. Flow A,containing hafnium tetrachloride and at least one carrier gas (e.g., Ar,N₂ and H₂), is pulsed sequentially with Flow B, containing water,hydrogen and an optional carrier gas. Flows A and B are each pulsed forabout 1 second and purge flows of argon are pulsed for about 1 secondbetween each pulse of Flows A and B. The temperature is maintained inthe range from about 250° C. to about 650° C.

[0069] In another example, a hafnium silicate film is grown by ALD inthe presence of hydrogen gas. Flow A, containing hafnium tetrachlorideand at least one carrier gas (e.g., Ar, N₂ and H₂), is pulsedsequentially with Flow B, containing water, hydrogen and an optionalcarrier gas and Flow C, containing Tris-DMAS and at least one carriergas. Flows A, B and C are each pulsed for about 1 second and purge flowsof argon are pulsed for about 1 second between each pulse of Flows A, Band C. The temperature is maintained in the range from about 450° C. toabout 650° C.

[0070] In another example, a hafnium silicon oxynitride film is grown byALD in the presence of hydrogen gas. Flow A, containing hafniumtetrachloride and at least one carrier gas (e.g., Ar, N₂ and H₂), ispulsed sequentially with Flow B, containing water, hydrogen and anoptional carrier gas and Flow C, containing Tris-DMAS and at least onecarrier gas and Flow D, containing a nitrogen plasma and an optionalcarrier gas. Flows A, B, C and D are each pulsed for about 1 second andpurge flows of argon are pulsed for about 1 second between each pulse ofFlows A, B, C and D. The temperature is maintained in the range fromabout 450° C. to about 650° C.

[0071] Materials are deposited by dosing chemicals separately in analternating fashion to achieve the desired film composition orcharacteristics with selected half reactions. The above half reactions,however, do not dictate the exact bonding connectivity or thestoichiometry of the resulting film. Stoichiometry is largely controlledby thermodynamics; however, kinetically controlled films may beachieved. Thus, the dosing sequence may be modified to effect theoverall composition and qualities of the film. The types of thin-filmmaterials that can be grown with ALD half reactions generally are:

[0072] 1. Binary Materials: Repetitive cycles of reactants {A+B}: e.g.,Hf₃N₄

[0073] 2. Direct Alloys: Repetitive cycles of reactants {A+B+C+D}: e.g.,HfSiO₄

[0074] 3. Compositionally Controlled Alloys: Repetitive cycles ofreactants {y(A+B)+z(C+D)} (where either y or z=1 and either z or yis >1, respectively): e.g., Hf_(x)Si_((2-x))O₄

[0075] 4. Compositionally Controlled Gradient Materials: Similar to 3,however, y or z is varied during deposition.

[0076] 5. Layered or laminate materials: Deposition of two differentmaterials in discrete physical layers. Repetitive cycles of reactants{y(A+B+C+D)+z(E+F)} (where y and z are typically ≧4): e.g.,nanolaminates of hafnia and alumina

[0077] ALD of Hafnium Aluminates (Hf_(X)Al_(Y)O)

[0078] Direct: 1 cycle=(TDEAH+H₂O+TMA+H₂O)

[0079] half reactions (s)=4.03+5.03+4.08+5.08

[0080] Compositionally Controlled: 1 cycle=n(TDEAH+H₂O)+m(TMA+H₂O) wheretypically n is one and m is varied or m is one and n is varied.

[0081] half reactions (second) (e.g., n=3,m=1)=4.03+5.03+4.07+5.07+4.07+5.07+4.08+5.08

[0082] Layered: 1 layer=p(TDEAH+H₂O)+q(TMA+H₂O) where p and q aretypically ≧4 half reactions (second) (e.g., n=4,m=4)=4.03+5.03+(4.07+5.07+4.07+5.07+4.07+5.07)+4.08+5.08+(4.04+5.04+4.04+5.05+4.04+5.04)

[0083] ALD of Hafnium Nitrides (Hf₃N₄ or HfN)

[0084] Direct: 1 cycle=(TDEAH+NH₃).

[0085] half reactions (second)=7.02+8.02

[0086] In this case, deposition at these temperatures may produce Hf₃N₄.Annealing to higher temperatures may produce HfN.

[0087] ALD of hafnium oxynitrides (HfO_(x)N_(y))

[0088] Direct: 1 cycle=(TDEAH+H₂O+TDEAH+NH₃)

[0089] half reactions (second)=7.02+9.02+4.07+6.07

[0090] Compositionally Controlled: 1 cycle=n(TDEAH+H₂O)+m(TDEAH+NH₃)where typically n is one and m is varied or m is one and n is varied.

[0091] Layered: 1 layer=p(TDEAH+H₂O)+q(TDEAH+NH₃) where p and q aretypically ≧4

[0092] ALD of Hafnium Aluminum Oxynitrides (Hf_(w)Al_(x)O_(y)N_(z))

[0093] Direct: 1 cycle=(TDEAH+NH₃+TMA+H₂O) hafnium oxynitride/aluminaoxynitride alloy

[0094] Variations possible: 1 cycle=(TDEAH+NH₃+TDEAH+H₂O+TMA+H₂O)

[0095] Note: The different dosing sequence effects the bondingconnectivity, especially when grown at lower temperatures <300° C. andwithout a higher-temperature anneal. In the top example, one mightpredict —O—Hf—N—Al—O— connectivity. This may be thought of as a hafniumoxynitride/aluminum oxynitride alloy. In the bottom example, one mightpredict —O—Hf—N—Hf—O—Al—O— connectivity. This may be thought of as ahafnium oxynitride/alumina alloy.

[0096] ALD of Hafnium Silicates (HfSiO₄ and Hf_(x)Si_(y)O)

[0097] Direct: 1 cycle=(TDEAH+H₂O+TrisDMAS+H₂O)=HfSiO₄

[0098] Silica-rich hafnium silicates: 1cycle=(TDEAH+H₂O)+3(TrisDMAS+H₂O)=Hf₂Si₅O₁₄

[0099] Compositional control (Hf:Si) from pure HfO₂ to silica-rich(>70%) hafnium silicates are possible.

[0100] ALD of Aluminum Silicate (Al₆Si₂₁₃ and Al_(x)Si_(y)O)

[0101] Direct: 1 cycle=(TMA+H₂O+TrisDMAS+H₂O)=Al₆Si₂O₁₃

[0102] Silica-rich aluminum silicates: 1cycle=(TMA+H₂O)+3(TrisDMAS+H₂O)=Al₂Si₂O₇

[0103] Compositional control (Al:Si) from pure Al₂O₃ to silica-rich(>50%) aluminum silicates are possible.

[0104] ALD of Hafnium Aluminum Silicate (Hf₂Al₆Si₄O₂₁ andHf_(x)Al_(y)Si_(z)O)

[0105] e.g., 1cycle=(TDEAH+H₂O+TrisDMAS+H₂O+TMA+H₂O+TrisDMAS+H₂O)=Hf₂Al₆Si₄O₂₁

[0106] ALD of Hafnium Silicon Nitride (HfSi_(x)O_(y)N_(z))

[0107] Direct: 1 cycle=(TDEAH+NH₃+TrisDMAS+NH₃)

[0108] ALD of Hafnium Silicon Oxynitride (HfSi_(x)O_(y)N_(z))

[0109] e.g., (TDEAH+H₂O+TrisDMAS+NH₃)

[0110] e.g., (TDEAH+NH₃+TDEAH+H₂O+TrisDMAS+H₂O+TrisDMAS+NH₃)

[0111] ALD of Aluminum Silicon Oxynitride (AlSi_(x)O_(y)N_(z))

[0112] e.g., (TMA+H₂O+TrisDMAS+NH₃)

[0113] ALD of Hafnium Aluminum Silicon Oxynitride(HfAl_(w)Si_(x)O_(y)N_(z))

[0114] e.g., (TDEAH+NH₃+TMA+H₂O+TrisDMAS+H₂O)

[0115] e.g., (TDEAH+NH₃+TDEAH+H₂O+TrisDMAS+NH₃+TMA+H₂O)

[0116] Continuous ALD of silica (SiO₂)

[0117] e.g., Direct: 1 cycle=Si(NCO)₄+H₂O

[0118]  This process may allow laminate layers of pure SiO₂ or more easycontrol of Si concentration in mixed allows. Si(NCO)₄ is very reactivewith Hf—OH* groups making silica incorporation easy (since TDEAH isreactive with SiOH*).

[0119] e.g., Consider several (TrisDMAS+H₂O) cycles with an occasional(TDEAH+H₂O) or (TMA+H₂O) cycle or (flash anneal>700° C.+H₂O) to reformsurface hydroxal groups to reinitiate growth.

[0120] Si₃N₄, (e.g. Non-Continuous Seed Layer or Capping Layer)

[0121] e.g., Direct: 1 cycle=(TrisDMAS+NH₃)

[0122] Si_(x)O_(y)N, (e.g., Non-Continuous Seed Layer or Capping Layer)

[0123] e.g., Direct: 1 cycle=(TrisDMAS+NH₃+TrisDMAS+H₂O)

[0124] AlN

[0125] e.g., 1 cycle=(TMA+NH₃)

[0126] Al_(x)Si_(y)N:

[0127] Al_(x)O_(y)N:

[0128] Hf_(x)Al_(y)N:

[0129] While the foregoing is directed to embodiments of the presentinvention, other and further embodiments of the invention may be devisedwithout departing from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

1. A method for forming a layer comprising hafnium on a substratesurface, sequentially comprising: a) exposing the substrate surface to ahafnium precursor to form a hafnium containing layer on the substratesurface; b) purging the chamber with a purge gas; c) reacting a secondprecursor with the hafnium containing layer; d) purging the chamber withthe purge gas; e) reacting a third precursor with the hafnium containinglayer; f) purging the chamber with the purge gas; g) reacting a fourthprecursor with the hafnium containing layer; and h) purging the chamberwith the purge gas.
 2. The method of claim 1, wherein the layercomprising hafnium is hafnium silicon oxynitride.
 3. The method of claim1, further comprising repeating steps a-h to deposit the layercomprising hafnium at a thickness from about 2 Å to about 1,000 Å. 4.The method of claim 3, wherein the thickness is from about 10 Å to about50 Å.
 5. The method of claim 1, wherein the hafnium precursor isselected from the group consisting of (Et₂N)₄Hf, (Me₂N)₄Hf, (EtMeN)₄Hfand Cl₄Hf.
 6. The method of claim 5, wherein the second precursor isselected from the group consisting of ammonia, hydrazines, azides andradical nitrogen compounds.
 7. The method of claim 6, wherein the thirdprecursor is selected from the group consisting of SiH₄, Si₂H₆, Si₃H₈,Si₂Cl₆, (Et₂N)₄Si, (Me₂N)₄Si, (Et₂N)₃SiH and (Me₂N)₃SiH.
 8. The methodof claim 7, wherein the fourth precursor is selected from the groupconsisting of H₂O, H₂O₂, organic peroxides, O, O₂, O₃ and radical oxygencompounds.
 9. The method of claim 1, further comprising: i) reacting afifth precursor with the hafnium containing layer; and j) purging thechamber with the purge gas.
 10. The method of claim 9, wherein the fifthprecursor is selected from the group consisting of Me₃Al, Me₂AlH, AlCl₃,Me₂AlCl and (PrO)₃Al.
 11. A method for growing a layer comprisinghafnium, comprising: exposing a substrate sequentially to at least fourprecursors during an ALD cycle to deposit a compound film comprisinghafnium and at least three elements selected from the group consistingof silicon, aluminum, oxygen and nitrogen.
 12. The method of claim 11,wherein the at least four precursors include a hafnium precursorselected from the group consisting of (Et₂N)₄Hf, (Me₂N)₄Hf, (EtMeN)₄Hfand Cl₄Hf.
 13. The method of claim 11, wherein the at least fourprecursors include a silicon precursor selected from the groupconsisting of SiH₄, Si₂H₆, Si₃H₈, Si₂Cl₆, (Et₂N)₄Si, (Me₂N)₄Si,(Et₂N)₃SiH and (Me₂N)₃SiH.
 14. The method of claim 11, wherein the atleast four precursors include a nitrogen precursor selected from thegroup consisting of ammonia, hydrazines, azides and radical nitrogencompounds.
 15. The method of claim 11, wherein the at least fourprecursors include an oxygen precursor selected from the groupconsisting of H₂O, H₂O₂, organic peroxides, O, O₂, O₃ and radical oxygencompounds.
 16. The method of claim 11, wherein the at least fourprecursors include an aluminum precursor selected from the groupconsisting of Me₃Al, Me₂AlH, AlCl₃, Me₂AlCl and (PrO)₃Al.
 17. The methodof claim 11, wherein the layer comprising hafnium is deposited to athickness from about 2 Å to about 1,000 Å.
 18. The method of claim 17,wherein the thickness is from about 10 Å to about 50 Å.
 19. A method fordepositing a hafnium compound on a substrate in a chamber during anatomic layer deposition process, comprising: conducting a first halfreaction comprising a hafnium precursor; conducting a second halfreaction comprising an oxygen precursor; conducting a third halfreaction comprising a nitrogen precursor; and conducting a fourth halfreaction comprising a silicon precursor.
 20. The method of claim 19,wherein the hafnium precursor is selected from the group consisting of(Et₂N)₄Hf, (Me₂N)₄Hf, (EtMeN)₄Hf and Cl₄Hf.
 21. The method of claim 20,wherein the silicon precursor is selected from the group consisting ofSiH₄, Si₂H₆, Si₃H₈, Si₂Cl₆, (Et₂N)₄Si, (Me₂N)₄Si, (Et₂N)₃SiH and(Me₂N)₃SiH.
 22. The method of claim 21, wherein the nitrogen precursoris selected from the group consisting of ammonia, hydrazines, azides andradical nitrogen compounds.
 23. The method of claim 22, wherein theoxygen precursor is selected from the group consisting of H₂O, H₂O₂,organic peroxides, O, O₂, O₃ and radical oxygen compounds.
 24. Themethod of claim 19, further comprising conducting a fifth half reactioncomprising an aluminum precursor selected from the group consisting ofMe₃Al, Me₂AlH, AlCl₃, Me₂AlCl and (PrO)₃Al.
 25. A composition of asemiconductor material, comprising HfSi_(x)O_(y)N_(z), wherein x is atleast about 0.2 and less than about 4; y is at least about 0.5 and lessthan about 4; and z is at least about 0.05 and less than about 2.